Densitometric determination of metoprolol tartrate in pharmaceutical dosage forms

This paper describes a simple densitometric method for the determination of metroprolol tartrate in tablets and ampoules. After separation on silica gel GF254 plates, using acetone-methanol-triethylamine as the mobile phase for the tablets and acetone-triethylamine for ampoules, the chromatographic zones corresponding to the spots of metoprolol were scanned. Quantitation was performed using a computer-controlled Camag TLC scanner and applying five-point calibration with polynomial regression. The calibration function was established in the ranges 1-28 micrograms for tablets and 1-9 micrograms for ampoules. The results obtained are precise and reproducible, with recovery values of 99.1-99.4%.